1. Field of the Invention
The present invention relates to a self-sealing plastic valve for inserting gas into an inflatable non-latex balloon and for sealing such a balloon after inflation. The present invention also relates to an inflatable non-latex balloon incorporating such a valve. The present invention further relates to a method for manufacturing such valves and for producing balloons incorporating such valves. The valves are especially characterized by inlets which flare or otherwise curl outwardly.
2. Related Art
As used herein, and as well-known in the prior art, the term "balloon" means an inflatable toy or other non-latex inflatable device, typically made of plastic sheet material which is generally non-elastic relative to rubber latex. A balloon typically includes a balloon body and may also have a balloon stem. Such a balloon normally is made from two flexible plastic (or non-latex) sheets which are cut and sealed together so as to produce various designs and configurations. The material from which the balloon is made is highly impermeable, but very thin. It is often referred to as non-latex, because it lacks the highly elastic properties of rubber latex.
Balloons are inflated using a gas supply mechanism, usually a type of nozzle. The nozzle may be inserted directly into the balloon, between the sheets of balloon material, to inflate the balloon. The balloon, however, may be equipped with a valve. If it is so equipped, the gas supply mechanism may be inserted into the valve, between the two plastic valve sheets. Such valves must be extremely thin and flexible, because part or all of the valve must be inserted and lie between the sheets of balloon material.
One balloon described in the prior art has a balloon body and a balloon stem, and employs a self-sealing valve fabricated from plastic sheet material. The valve is incorporated into the balloon and the inlet ends of the valve sheets are completely fused or bonded to the balloon material so that there are no free inlet ends of the valve and the valve lies entirely within the balloon. The valve cannot function if the inlet ends of both plastic valve sheets are not bonded to the respective balloon film sheets. The gas supply mechanism is inserted into the balloon stem into a passageway formed between the sheets of balloon material. The passageway, when opened apart, then opens the valve for the gas to pass through to inflate the balloon body. The valve is not used for insertion of the gas supply mechanism.
In another prior art balloon with a self-sealing valve, the valve is surrounded by balloon material, i.e., the balloon stem. However, the valve is exposed through an opening in the balloon material so that the gas supply mechanism is inserted into the valve between the valve sheets, rather than between the sheets of balloon material.
Another prior art balloon incorporates a self-sealing valve in which the inlet end of the valve hangs freely outside the balloon, extending from the balloon body or the balloon stem. The gas supply mechanism is inserted into the valve between the valve sheets, which enables gas to flow into and inflate the balloon body.
Because of the thinness of the valve sheets used to form valves for use with inflatable non-latex balloons, problems have arisen in separating the two valve sheets of a valve in order to insert a gas supply mechanism. Insertion and separation problems frequently cause the valves to be torn or punctured, thereby diminishing or ending their utility. Also, the valve sheets tend to stick together, causing difficulty and delay in inflating the balloon. This is especially the case where the two valve sheets which make up a valve are coterminous at the inlet end of the valve, i.e., one valve sheet does not extend beyond the end of the other.
One known method for producing balloons incorporating self-sealing valves relies upon the valve having valve sheets of different lengths. The longer sheet has an extension, or positioning tab, at the inlet end of the valve. The positioning tab is used to position the valve to lie entirely within the balloon. This method of making a balloon, however, has several disadvantages. First, sheets used for the valve must have non-coterminous inlet ends. Second, since the valve lies entirely within the balloon, it is not visible to a person looking at the balloon in its finished state, or during manufacture of the balloon. Thus, during manufacture it cannot be readily or easily known whether the valve is actually or properly placed into the balloon. Third, it cannot be readily determined whether the valve sheets are completely or properly fused to the balloon material, so as to enable gas to flow through the balloon stem and then through the valve. These problems can frequently result in a balloon having no valve or a misplaced valve, such that a defective balloon is sold to customers.
It is apparent from the above discussion of the prior art that serious problems remain in the manufacture and structure of self-sealing valves and of non-latex balloons incorporating such valves. Better valves for such balloons are a particular need.